In recent years, electronic apparatus incorporating a touch panel have come into wide use. And touch panels which enable users to make intuitive manipulations have come to be used widely as devices for receiving input manipulations on electronic apparatus including cellphones. Touch panels enable, through the same screen of a display unit (e.g., LCD (liquid crystal display) or organic EL (electroluminescence) display) provided in an electronic apparatus, reception of an input manipulation on the screen and display processing for a processing result of the electronic apparatus.
Touch panels are also known which can detect coming into proximity of a finger (refer to Patent document 1, for example). Touch panels of this kind can detect a state that a finger is placed over the touch panel at a height position that is spaced from the touch panel by a certain distance, that is, a state of proximity of a finger to the touch panel, and can detect a manipulation that a finger is slid approximately parallel with the touch panel on the basis of a capacitance that is determined by a distance between the finger and the touch panel like a manipulation that a finger is slid being kept in direct contact with the touch panel. As such, touch panels capable of detecting coming into proximity of a finger are expected to become a new user interface.
The non-contact user input device disclosed in Patent document 1 include plural linear transmission electrodes, a transmitter for supplying transmission AC currents to the respective transmission electrodes, plural linear reception electrodes disposed so as not to be in contact with the transmission electrodes, and a receiver for receiving AC currents that flow through the respective reception electrodes. Capacitors are formed at the crossing points of the transmission electrodes and the reception electrodes and capacitors are formed as a fingertip of the user comes closer. Therefore, the capacitances of the capacitors vary according to the degree of proximity of the finger. The non-contact user input device can recognize the distance between the touch panel and the finger on the basis of variations of the capacitances.